[PHP] "Just nu tittar x på denna sida"-funktion?

Jobbar mot en DB, se nedanför PHP-skriptet

dokumentet__________________________________

<?php 
/* start session, connect to db, select db, set save time(seconds) */ 
session_start(); 
mysql_connect("host","user","password"); /* put your own settings here */ 
mysql_select_db("database"); /* put your own settings here */ 
$intSavetime   = 20; /* seconds a user should be considerd online */ 

/* first delete all old posts */ 
mysql_query("DELETE FROM currentUsers WHERE time<" . time()) or die(mysql_error()); 

/* get amount of users online */ 
$sqlNum      = mysql_num_rows(mysql_query("SELECT id FROM currentUsers WHERE ip='" . $_SERVER['REMOTE_ADDR'] . "' AND sess='" . session_id() . "'")); 

/* slq query's for update/new entries in db */ 
$sqlUpdate      = "UPDATE currentUsers SET time='" . (time()+$intSavetime) . "' WHERE ip='" . $_SERVER['REMOTE_ADDR'] . "' AND sess='" . session_id() . "'"; 
$sqlNew         = "INSERT INTO currentUsers (ip,sess,time) VALUES ('" . $_SERVER['REMOTE_ADDR'] . "','" . session_id() . "','" . (time()+$intSavetime) . "')"; 

/* update/insert new entry in db */ 
if($sqlNum > 0){ 
   mysql_query($sqlUpdate) or die(mysql_error()); 
}elseif($sqlNum == 0){ 
   mysql_query($sqlNew) or die(mysql_error()); 
}else{ 
   echo "<b>Something realy wierd just happend</b>"; 
} 

/* define constant */ 
define("_USERS_ONLINE_",mysql_num_rows(mysql_query("SELECT id From currentUsers"))); 


/* 
* EXAMPLE OUTPUT: 
*/ 
echo "<br />Users: " . _USERS_ONLINE_; 
?> 


databasen______________________________________________________

CREATE TABLE `currentUsers` ( 
  `ip` varchar(255) NOT NULL default '', 
  `sess` varchar(255) NOT NULL default '', 
  `time` varchar(250) NOT NULL default '', 
  `id` int(11) NOT NULL auto_increment, 
  PRIMARY KEY  (`id`) 
) TYPE=MyISAM AUTO_INCREMENT=1 ;